Investigate the Effect of Osmotic Dehydration Pretreatment towards Freeze Dried Strawberries at PT Frootiful Natural Nusantara

Abstract

PT Frootiful Natural Nusantara is a company that produces freeze dried fruits products sold in the store and online market-place. Freeze drying is a drying method to preserve food products with minimum loss of vitamins and other micronutrients, as well as retaining its shape. Strawberries are high in moisture content (87% - 93% w/w) and low in total sugar content (5% - 10% w/v). Therefore, the results of FD (freeze-dried) strawberries are relatively low in yield and have a sour taste. The objective of this study is to find the suitable sugar concentration of osmotic dehydration method and types of strawberries used, in terms of yield and sensory properties including sweetness, texture, color, and shape of FD strawberries. The experiment was conducted using fresh and frozen strawberries, immersed in 60%, 100%, and 200% of sucrose solution for 24 hours at ambient temperature. The analysis includes the measurement of weight after immersion, yield after freeze drying, and FGD sensory evaluation with 5 internal panelists. The weight after immersion of both osmodehydrated fresh and frozen strawberries have the same trend, where the increment of sucrose concentration, the greater weight loss achieved, and therefore the lighter the weight of the strawberries. Meanwhile, the yield of FD osmodehydrated fresh and frozen strawberries also have the same trend in which higher sugar concentration resulted in higher yield. Increasing sucrose concentration also increases the sweetness and texture (hardness) of the FD osmodehydrated strawberries. Whereas shape and color did not affected by the osmotic dehydration pretreatment. The most suitable concentration and types of strawberries used in this experiment was fresh strawberries immersed in 100% of sugar solution for 24 hours. Therefore, the osmotic dehydration pretreatment has successfully increased the yield and sensory properties of FD strawberries.